Effect of stabilizers on the chemical and photodegradation of ascorbic acid in aqueous solution

Ascorbic acid [vitamin C] is susceptible to light and air and forms various degradation products. A number of stabilizers have been used to study their effect on the degradation of ascorbic acid [AH2] in dark and light at pH 4.0 and 6.0 alone and in combination with citric and tartaric acids. The assay of AH2 in degraded solutions was performed by a specific UV spectrometric method. The degradation product of AH2 at pH 4.0 and 6.0 was identified as dehydroascorbic acid. The degradation of AH2 has been found to follow first-order kinetics. The apparent first-order rate constants, t90 and percent inhibition in rate in the presence of stabilizers and the second-order rate constants for the interaction of stabilizers with AH2 have been determined. The highest stabilizing effect on AH2 was found by sodium metabisulfite, followed by sodium sulfite, sodium bisulfate, sodium thiosulfate and thiourea. The pH of the solutions has also been found to influence the degradation of AH2 as the rates are higher at pH 6.0 compared to those of pH 4.0, probably due to the ionization of AH2. A synergistic effect has been observed when citric or tartaric acid was added to the solutions containing stabilizers where citric acid showed comparatively better effect

Prevalence and therapy of chronic obstructive disease in Karachi

Background: Chronic obstructive pulmonary disease [COPD] has boon one of the main causes of mortality worldwide. The impact of COPD has been increasing socio-economically over time to make COPD an alarming condition for health associated professionals due to the severity of prevalence and its expensive treatment. Due to COPD, patients not only suffer from the illness as the financial costs associated with it

Objective: To determine the prevalence and the medication of COPD

Methods: The medical records of patients suffering from COPD were collected from different tertiary care hospitals in Karachi from June 2011 to May 2012 comprising of middle adulthood to mature aged patients

Results: Out of 1260 patients 174 [13.60 %] were suffered from COPD. Nearly all the patients of COPD were associated with co-morbidity like diabetes mellitus, hypertension, urinary tract infections, renal failure, pneumonia, cardiovascular diseases, and other diseases. Ant-allergy, oxygen supply, intravenous and oral montilukast, atrovent and other nebulizers, cough syrups, inhalers, antibiotics, and other treatment were used for the treatment of COPD as directed by the world renowned guidelines for COPD

Conclusion: The prevalence of COPD is high and is detected through a standalone pulmonary function test [PFT] e.g Spirometry, or in conjugation with a clinical examination. In most oases the guidelines provide by the British Thoracic Society, Americans Thoracic Society, and European Respiratory Society are used to treat COPD

Pharmaceutical care - an essential component of healthcare system

The present review deals with the definition, importance and fundamental aspects of pharmaceutical care. Pharmaceutical care is an integral part of healthcare system in the provision of medication related care to achieve the optimal therapeutic outcomes for the patient and his quality of life. It has many advantages including the reduced chances of medication errors, increased patient compliance in medication regimen, appropriate management and to build strong relationship between the pharmacist and the patient. The various aspects of pharmaceutical care involving the patients and their requirements for adherence to pharmacotherapy have been discussed. The pivotal role of pharmacists in pharmaceutical care has been emphasized. Patient's satisfaction with the pharmaceutical services acquiring optimal therapeutic outcomes is a key element in pharmaceutical care. Future prospects of pharmaceutical care have also been highlighted

Stabilization of drugs in pharmaceutical preparations

Drug substances may undergo chemical degradation which may result in the loss of potency and therapeutic activity. Drugs are often sensitive to environmental and chemical factors such as oxygen, temperature, humidity, light, pH, ionic strength, solvent, buffers and excipients. The degraded products may produce undesirable effects as well as toxic effects on the body. The delivery of stabilized formulated products is a necessary requirement for the optimum efficacy of the active drug. The drugs are usually stabilized by chelating agents, complexing agents, bio-polymers, naturally occurring protectors, encapsulation of drugs and use of antioxidants. It has been found that hydrolytic and oxidative degradation are the main routes of loss of active ingredients. Solid preparations are usually stabilized by complex formation while in some liquid and semi-solid preparations there is a need to consider other factors such as pH, solvents for the stabilization of the drugs

Recent advancements in the clinical use of aspirin

Aspirin [acetylsalicylic acid] is a widely used drug that possesses analgesic activity. It is effective in the treatment of pain, inflammation and fever. In addition to these ailments aspirin has been found to be useful in the treatment of other diseases including cell apoptosis and colorectal cancer, Kawasaki disease, migraine and cardiovascular diseases. The mechanism of action of aspirin is due to its ability to suppress the production of prostaglandin and thromboxanes as a result of its irreversible inactivation of cyclo-oxygenase [COX] enzyme

Photodegradation of cyanocobalamin in the presence of ascorbic acid

The photodegradation of cyanocobalamin at pH 4.0 in the presence of ascorbic acid has been studied. Hydroxocobalamin has been identified as a major degradation product of the reaction. Cyanocobalamin and hydroxocoblamin in degraded solutions have been assayed at 550 and 525nm by a two-component spectrophotometirc method in which ascorbic acid does not interfere. The apparent first-order rate constants for the photodegradation of cyanocoblaamin at pH 4.0 are in the range of 2.21-2.70 x 10-3 min-1. These values indicate that the photodegradation of cyanocobalamin is enhanced in the presence of ascorbic acid by mutual interaction and needs protective measures to control the degradation of the vitamin

Levofloxacin: a broad spectrum potent antibiotic

Levofloxacin is a third generation· fluoroquinolone antibacterial agent with a broad spectrum activity against Gram-positive, Gram-negative bacteria and atypical pathogens. It shows its bactericidal activity by inhibiting topoisomerase IV and DNA gyrase. Levofloxacin has shown Strong antibacterial action against Staphylococcus species, Streptococcus pyogenes, Streptococcus pneumoniae. Staphylococcus haemolyticus, Enterobacter species, Escherichia coli, Salmonella species Klebsiella species Serratia species, Enterococcus species; Proteus. Species, Pseudomonas aeruginosa, Haemophilus injluenzae and Neisseria gonorrhoea. Moreover, levofloxacin has shown antifungal activity against Chlamydia trachomatis it is also active against penicillin resistant Streptococcus pneumoniae. It also possesses lethal effect on resistant mycobacteria like Mycobacterium tuberculosis and Mycobacterium leprae causing tuberculosis and even Mycoplasma species of HIV infection. Levofloxacin is indicated in the treatment of urinary tract infection, respiratory tract infection, biliary tract 'infection and other infection with clinical efficacy of 80-92%

Physicochemical, biochemical and antioxidant properties of ascorbic acid

Ascorbic acid [Vitamin C] is an important micronutrient that plays as a redox cofactor and catalyst in biological system. It is particularly useful in the cure and prevention of scurvy. It was originally isolated from lemon, cabbage and peprica. Ascorbic acid is essential for collagen formation and metabolism of phenyl alanine, tyrosine and hydroxyphenyl alanine [dopa]. The minimum daily requirement of vitamin C in adult is 40-60 mg. In this review chemical structure, physicochemical characteristics, chemical stability, biochemical functions and antioxidant activity of ascorbic acid have been mentioned

Botulinum toxin: biochemical aspects, applications and adverse effects

Botulinum toxin is one of the most potent bacterial toxins known and its effectiveness in the treatment of some pain syndromes is well documented. However, the efficacy of some of its indications is still in the process of being confirmed. Botulinum toxin, a neurotoxin with high affinity for cholinergic synapses, blocks the release of acetylcholine by nerve endings without interfering with neuronal conduction of electrical signals or synthesis and storage of acetylcholine. It has been proven that botulinum toxin can selectively weaken painful muscles, interrupting the spasm-pain cycle. In cosmetics, a small dose of botulinum toxin can be used to prevent formation of wrinkles by paralyzing facial muscles. Botulinum toxin has been categorized into seven types, of which type-A preparations are currently the most widely used. In addition to the clinical and cosmetic uses of botulinum toxin, a number of adverse reactions have also been reported; therefore, it should be used with caution

Biochemical Importance, Deficiency and Clinical Assay of Cyanocobalamin

The present review describes the biochemical importance of cyanocobalamin [vitamin B12] and its role in the biosynthesis of adenosylcobamide and methylcobamide co-enzymes which perform important functions in human metabolism. Cyanocobalamin deficiency is a significant public health problem particularly among the elderly. It has been reported that the prevalence of vitamin B12 deficiency may be as high as 30-40% among the elderly due to food B12 malabsorption. Various analytical methods have been used for the clinical assay of cyanocobalamin in biological samples. These include microbiological, radioisotope, spectrophotometric and chromatographic methods